Refrigerator is a vital food storage techniques around the world. The lower temperature reduces the increasing bacterial rate in the fridge. It also reduces the rate of food spoilage. A refrigerator maintains a proper temperature a few degrees above the freezing point of the water. The minimum temperature range of food storage is 3 to 5 degrees Celsius. Therefore a similar machine that maintains a temperature below the freezing point of water is known as a freezer. The refrigerator replaces the icebox, which had been a similar household appliance for almost an entire century and a half.